The present invention is directed broadly to apparatus for altering sound energy in the form of passively reducing noise emitted from appliances for residential and commercial settings and, more particularly, to an apparatus for altering sound energy in a manner that passively reduces such sound energy in the form of noise produced during the operation of residential or home appliances.
In the present case, passive noise reduction refers to noise reduction without input to the appliance at issue. On the other hand, an active noise reduction system provides some sound negating input to the appliance, either electrical or in the form of cancelling sound wave energy.
Large household appliances such as dishwashers, refrigerators, laundry machines, including washers and dryers, and even smaller household appliances such as oven hood vent fans, wine coolers, espresso-making apparatus, food mixers, food processors, juice centrifuges, juice extractors, and waste masticators all emit a certain amount of sound in the form of noise in connection with the operation of fans, electric drive motors, pumps, compressors, or other customary components of such appliances. Such sound emissions may be objectionable as noise to some and to others may just appear as loud sound energy. The use and accommodation of such appliances within residences and other settings would be improved if there existed a capability to selectively alter the sound level including altering the sound level to a reduced (lower decibel) level.
To that end, much time and effort has already been expended in providing insulation for sound producing components of such appliances, in providing more balancing of such sound producing components, and in more efficiently using electricity so as to reduce the emitted noise. The insulation helps to reduce the noise heard outside of the sound producing device and, indeed, much progress has been made in reducing noise from household appliances. On the other hand, it is generally understood that to further lower noise or sound emissions from these appliances would be desirable and will in fact advance the desired goal of full seamless integration of such appliances into the full range of residential and commercial settings. It would therefore be desirable if other methods and apparatus beyond the known insulation, balancing, and energy efficiency approaches were available to help reduce the sound level emitted from such sound producing home appliances.